From: Feng Tang <feng.tang@intel.com>
Date: Tue, 12 Mar 2013 03:56:47 +0000 (+0800)
Subject: x86: tsc: Add support for new S3_NONSTOP feature
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=82f9c080b22a5b859ae2b50822dfb6b812898fdb;p=linux-beck.git

x86: tsc: Add support for new S3_NONSTOP feature

Add support for new S3_NONSTOP feature

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 4b9ea101fe3b..098b3cfda72e 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -768,7 +768,8 @@ static cycle_t read_tsc(struct clocksource *cs)
 
 static void resume_tsc(struct clocksource *cs)
 {
-	clocksource_tsc.cycle_last = 0;
+	if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC_S3))
+		clocksource_tsc.cycle_last = 0;
 }
 
 static struct clocksource clocksource_tsc = {
@@ -939,6 +940,9 @@ static int __init init_tsc_clocksource(void)
 		clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS;
 	}
 
+	if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC_S3))
+		clocksource_tsc.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP;
+
 	/*
 	 * Trust the results of the earlier calibration on systems
 	 * exporting a reliable TSC.